were these day or not time shots you were trying to get? or were you in a very bright night time scene and wanting to keep the buildings and such from being over exposed?
I typically shoot night time lightning using 1 to 30 second exposures, ISO and aperture will shutter speed will depend on your surrounding ambient light and what over all shot you are going for.
I have only tried day time lightning 2 times, was able to get one bad shot, I could see using a lightning trigger for day time shots, but night time its so much fun to constantly move the camera and tweak the settings as you go. I set my camera to bulb mode and use a remote to keep taking shots.
this is a 36 second exposure @ iso 200 and F22 ( i think)
this is a 4 second exposure iso 200 F8
lightning can strike you from 10 miles away, so be careful and never be afraid to tuck your tail and run and hide. I have had to do that several times, but sometimes it just go close for comfort.
James